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PVT is it more efficient than PV?


zakzak
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Is the photovoltaic thermal hybrid solar collector (PVT) more efficient than the normal photovoltaic panels? Do you have some empirical data? Because many people are claiming that the PVT is more efficient than the PV modules, but I don't see any data. The information is theoretical: the efficiency of the solar panels decreases with heat and the pipes of the thermal layer absorb the heat coming from the PV layer, therefore, they should be more efficient. Which is true in principle but this is not enough, we need some experiments, some data.

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10 hours ago, zakzak said:

Is the photovoltaic thermal hybrid solar collector (PVT) more efficient than the normal photovoltaic panels? Do you have some empirical data? Because many people are claiming that the PVT is more efficient than the PV modules, but I don't see any data. The information is theoretical: the efficiency of the solar panels decreases with heat and the pipes of the thermal layer absorb the heat coming from the PV layer, therefore, they should be more efficient. Which is true in principle but this is not enough, we need some experiments, some data.

Can you please tell me more about this?

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On 13/07/2017 at 6:33 AM, zakzak said:

we need some experiments, some data.

I am quite willing to test them against my 3kW PV modules. But hang on my modules are 2 years old so that would be unfair. :D Send me 3kW of PV modules and 3kW of PVT modules and I will run a battery of tests. Oh talking of batteries my current bank is failing so a nice new Lithium bank is needed for the test.

My address is Chris Hobson Roodeberg Farm Kendrew - just hope the courier can find me :lol:

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27 minutes ago, ibiza said:

What about your Axpert? It takes only 3KW panels and PVT might produce more then that, so my advice is to  you is to ask for at least one Infinisolar Super.

I thought would not ask for an Axpert replacement on two scores

  1. Everyone might think I just wanted a massive freebie
  2. TTT would be given an opportunity to restart the Victron versus Axpert debate.

 

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2 hours ago, Chris Hobson said:

TTT would be given an opportunity to restart the Victron versus Axpert debate.

Nope, I'm done. Ek is klaar. :D

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9 hours ago, Chris Hobson said:

I thought would not ask for an Axpert replacement on two scores

  1. Everyone might think I just wanted a massive freebie
  2. TTT would be given an opportunity to restart the Victron versus Axpert debate.

 

Speaking of witch(es), I have a doubt where to go from where I am now.

My original plan was to start with cheap inverters in order to gain some knowledge about solar and to wait and give a chance:) inverter manufactures to develop better and cheaper machines as this is always happening with electronics. So this is my dilemma: Three 4kw Axperts a enough for me and I am looking for similar size og better inverters. Infinisolar Super x3 would be enough  for me Price is R60k but it is steel cheep manufacturer say it is Mazda. Victron (RR) Quattro 8000 cost similar amount of Rands but is little bit too  small. I couldn't find the supplier and the price in SA for Victron 10000 and this is where my problem lies.

I am calling good pplB)  to help me with some ideas.

Regards

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18 hours ago, ibiza said:

Victron (RR) Quattro 8000 cost similar amount of Rands but is little bit too  small.

Do you have a grid connection? Do you mind offloading the peaks to the grid? I ask, because one big overlooked difference is that while the Axpert is a UPS with a built-in MPPT (the inverter must be capable of carrying the peak on its own), the Multi/Quattro can tie with the grid and take the difference from the grid. If the majority if your loads is below 8kw or maybe even below 5kw, you can get away with a much smaller unit.

Also... if you can wait a while... there's always new developments in the pipeline :-)

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1 minute ago, zakzak said:

Does anyone have empirical data to confirm whether PVT are more efficient than PV or not?

I don't think anyone here has tried it or even know about it. The closest I've seen was an Italian heat pump product that had a collector that you mounted on the roof (improves the COP so you can get away with a smaller compressor unit). This collector could be mounted below existing PV panels. The marketing material said that by harvesting the heat in this manner it also improves the PV yield. Of course... that's marketing stuff. And in theory it is trivially true. But it is far from the empirical and/or real live numbers/experience you are asking for.

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24 minutes ago, plonkster said:

Do you have a grid connection? Do you mind offloading the peaks to the grid? I ask, because one big overlooked difference is that while the Axpert is a UPS with a built-in MPPT (the inverter must be capable of carrying the peak on its own), the Multi/Quattro can tie with the grid and take the difference from the grid. If the majority if your loads is below 8kw or maybe even below 5kw, you can get away with a much smaller unit.

Also... if you can wait a while... there's always new developments in the pipeline :-)

Thanks for very encouraging answer/advice. @plonksterThis is what I was looking for but wasn't sure I can afford one as everybody sais "Vector is very expensive" but compering with Infinisloar Super Victron looks much more acceptable.

Yes, I have a grid connection.

No, I don't mind offloading peaks to the grid!

Most of the loads are below 8kw ( between 5-7) so, I don't mind having Quattro 8KW if the price is not much higher than Q8000(6KW).

On the end I must thank you soooo much as this is exactly what I want/need!

 

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1 hour ago, plonkster said:

Do you have a grid connection? Do you mind offloading the peaks to the grid? I ask, because one big overlooked difference is that while the Axpert is a UPS with a built-in MPPT (the inverter must be capable of carrying the peak on its own), the Multi/Quattro can tie with the grid and take the difference from the grid. If the majority if your loads is below 8kw or maybe even below 5kw, you can get away with a much smaller unit.

Also... if you can wait a while... there's always new developments in the pipeline :-)

I am almost sure that you know some think rest of us don't, do you?:)

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Hi Ibiza

I would guess 90% of you loads are below 2kW and 85% are below 1kW.  I am with TTT smaller is better. Don't aim to run the big loads off solar you have a grid connection you don't have to.

If I was in an urban environment I would have a true-hybrid and be on solar during the day - Eskom at night and battery if the grid was down.

Being nearly self sufficient gives one tremendous peace of mind but it does come at a cost.

 

The above applies to residential installations, business or industrial installs change the goalposts and the rules.

 

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53 minutes ago, ibiza said:

I am almost sure that you know some think rest of us don't, do you?:)

I mean that in general the guys know who they are competing with and they are aware that Voltronic is improving their product and will continue to do so. Therefore there will be new models that will be more competitive. I cannot tell you when that will happen, what they will look like or what the price point will be :-)

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23 minutes ago, Chris Hobson said:

Hi Ibiza

I would guess 90% of you loads are below 2kW and 85% are below 1kW.  I am with TTT smaller is better. Don't aim to run the big loads off solar you have a grid connection you don't have to.

If I was in an urban environment I would have a true-hybrid and be on solar during the day - Eskom at night and battery if the grid was down.

Being nearly self sufficient gives one tremendous peace of mind but it does come at a cost.

 

The above applies to residential installations, business or industrial installs change the goalposts and the rules.

 

Hi @Chris Hobson, thanks for the respond. There are three families living in the house meaning 3 stoves,3 washing machines, two electric geysers and so on, and so on, multiplie by 3.

We use between 25-45kwh/day. I had two 4kw Axperts for one year than I added a third plus additional 12 250w panels and that setting is working just fine for me (except on cloudy days)

I am on solar during the day and on Eskom at night, and on the batteries if necessary.

My aim is also to buy a hybrid. Firstly the plan was to go for Infinisolar Super but 3 of them will cost me as much as one Quattro. So why would go for Mazda if I can have a RR for similar money!!?

And on the end: do you remember late Martin Luther King's saying :"I have a dream!" so I have one too, to show the finger to Eskom as I did to Hellcom.

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40 minutes ago, plonkster said:

I mean that in general the guys know who they are competing with and they are aware that Voltronic is improving their product and will continue to do so. Therefore there will be new models that will be more competitive. I cannot tell you when that will happen, what they will look like or what the price point will be :-)

And I meant you were talking about Victrom as you were/are in the Dutchland! :)

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3 hours ago, Chris Hobson said:

The above applies to residential installations, business or industrial installs change the goalposts and the rules.

 

3 hours ago, ibiza said:

Hi @Chris Hobson, thanks for the respond. There are three families living in the house meaning 3 stoves,3 washing machines, two electric geysers and so on, and so on, multiplie by 3.

This is more like an industrial install :D.

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On ‎7‎/‎15‎/‎2017 at 3:38 PM, ibiza said:

My aim is also to buy a hybrid. Firstly the plan was to go for Infinisolar Super but 3 of them will cost me as much as one Quattro. So why would go for Mazda if I can have a RR for similar money!!?

Remember to add the MPPT still probably looking at the 150/60 around another 8k x 3 for you then?

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21 minutes ago, viper_za said:

Remember to add the MPPT still probably looking at the 150/60 around another 8k x 3 for you then?

Thanks for reminder @viper_za, I must admit that I didn't count on extra chargers .:wub:. Well in that case I must go for Infinisolars again. Nothing wrong with Mazda but RR is RR.

 In next drawing I might have some more luck.

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On 14/07/2017 at 5:24 PM, ibiza said:

Speaking of witch(es), I have a doubt where to go from where I am now.

My original plan was to start with cheap inverters in order to gain some knowledge about solar and to wait and give a chance:) inverter manufactures to develop better and cheaper machines as this is always happening with electronics. So this is my dilemma: Three 4kw Axperts a enough for me and I am looking for similar size og better inverters. Infinisolar Super x3 would be enough  for me Price is R60k but it is steel cheep manufacturer say it is Mazda. Victron (RR) Quattro 8000 cost similar amount of Rands but is little bit too  small. I couldn't find the supplier and the price in SA for Victron 10000 and this is where my problem lies.

I am calling good pplB)  to help me with some ideas.

Regards

You can Always try to get best of both the world by using both Victron and Axperts. I have used Quattro  5KW for only one phase to power critical loads (Lighting , AV receiver, TV, Booster pump , wall sockets - expresso machine, vacuum , Mixer etcc) 

The 2 Axperts in parallel supply  10 KVA to only my 4 no of inverter  Aairconditioners and washing machine/dryers  ( had to separate the wiring though) but separating the Loads was much easier than paying for 3 Quattros :)

the rest of the stuff - Other Ac's Gardning supply , O/H water pump are on B phase 

In future, I will move only the Quattro to Lithium ( looking at FREEDOMWON) waiting for prices to drop below 150USD/KWH

I also have a 7.5 KVA genie to feed the Axpets through DC coupling essentially preventing SOC going Below 80 % 

In Nigeria, We are essentially Offgrid ( 2500 MW for 200 million people !!) average power availability is 40-50 Hours a week

solar setupMaster Layout with connections  JULY 2017.jpg

Edited by ghatikar
Added power availability
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5 hours ago, ghatikar said:

looking at FREEDOMWON

There's some new stuff going into the new MPPT firmware that will allow the BMS to control certain aspects of the MPPTs. Not officially released yet, still in testing, but as always only a firmware upgrade away :-)

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On 7/18/2017 at 9:06 PM, plonkster said:

I love how the Espresso machine is a critical load :-)

:) Cup of Joe comes first before lighting load in my Table of load calculations.

Back in 2008 I had selected 3.5 KVA inverter at astronomical price just so that my expresso timer would not reset overnight and the boiler was hot in the morning for the first cup.

The family was a;o happy as the DSTV decoder ( dualview at that time) also got fulltime power thus ensuring no missed recordings  

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